The present invention relates to improvements to the lighting systems. More in particular, the present invention relates to improvements useful in public lighting systems or, in general, in systems presenting a plurality of lighting units distributed over a wide area, such as, for instance, a street lighting system.
In lighting systems that are distributed over wide areas, such as, for instance, in the public street lighting systems for urban areas, airports or the like, there is a need to monitor the proper operation of the lighting elements to enable their rapid replacement in the event of their failure. to perform an automatic and continuous surveillance of such systems, it has been suggested (WO-A-2004/08887) to apply to each lighting element a control unit that powers the lamp and controls the proper operation thereof. In the event of a failure, the control unit, using power line communication over the power supply network, transmits a message to a collecting unit, by means of a power line modem (PLM). In this way, a plurality of lamps can be monitored continuously and, in the event of a fault, the collecting unit receiving the failure message notifies an operation center, by means of a radio communication, via GSM or other suitable means, in the case even via cable or fiber optics, so that the operation center can take action to repair the fault.
US 2005/0231125 describes a lighting system in which a control unit performs a test on the proper operation of the lamp with which it is associated and, at the same time, it dims the lamp following instructions received through the power supply network from a collecting or control unit. Also in this case, a PLM is provided for each control unit and for each of the one or more collecting units to enable the exchange of information, instructions and/or data, including information on any faulty operation of the lamp, via power line communication over the power supply network.